iOS apps use SSL. However: • HTTP protocol is still widely used (now over SSL) • iOS applications trust system certificate storage It looks like SSL is used mostly to prevent MitM-attacks (stealing passwords, cookies etc) that prevent sniffing traffic from your own device.
own “per-app” certificate storage. 2. There is no common implementation of the “per-app” storages (iOS apps hardcode certificates, keep certificates in external files, request certificates on first start and save to app bundle settings etc). 3. There is no common way to sniff SSL traffic anymore!
a MobileSubstrate extension. It hooks 3 important iOS SSL stack functions: • SSLSetSessionOption(...) • SSLCreateContext(...) • SSLHandshake(...) Of course, SSLKillSwitch is not the only tool of this kind, but I believe it’s first and most used.
app developers start to implement custom SSL validation techniques. The techniques include numerous features, e.g. 1. Pinning public keys (SubjectPublicKeyInfo (SPKI)) vs. certificate pinning 2. Client-side certificates 3. iOS SSL stack functions integrity check… 4. ...and so on SSLKillSwitch and similar tools are not the absolute weapon against SSL pinning anymore!